Relay instrument



July 26, 1932 g. s. EREMEEEF RELAX INSTRUMENT Filed June 18 1930 A TTORNEYS.

hibiting means,

PatentedA July '1932A I UNITED STATES PafrElarv OFFICE `IVAN I.- EBEMEEFF, F PHILADELPHIA, PENNSYLVANIA, ASSIGNOB T0 THE BROWN INSTRUMENT COMPANY, 0F PHILADELPHIA PENNSYLVANIA, A. CORPORATION OF PENNSYLVANIA RELAY INSTRUMENT Application mea :une 1S, 1930. serial No. 461,934.

The general object of my present invention is to provide a potentiometer measuring instrument with improved means characterized by their relative simplicity and effectiveness for performing operative functions hereto-v fore effected in such instruments by the use of more complex mechanism.

`More specifically the object of the present invention is to-provide improved means for adjusting the potentiometer instrument ex- Which may comprise an indicator or recording element, and usually comprises both of such elements, and for adjusting the point of engagement of the main potentiometer slide Wire resistance and its cooperating contact, when the deflections of a galvanometer associated with the potentiometer indicate the necessity forsuch adjustments.

v The various features of novelty which characterize myinvention are pointed out with particularity in the claims annexed to and forming a part of this specification. For

,shown in Fig. l.

a better understanding of the invention,

however, and the advantages possessed by. it,

reference should be had to the accompanying I The rotative speeds of the shafts R and C, and

drawing and descriptive matter in which have illustrated and described a preferred embodiment of the invention.

Of the drawing 2- Fig. l is a perspectiveview of a potentiometer instrument with and removed/to render ot er parts ofthe instrument more readily visible;

Fig. 2 is a sectional elevation of a portion of the vapparatus shown in Fig. l; and

Fig. 3 is a perspective view illustrating a modification of` a portion of the apparatus ln Fig. l I have shown a recording potentiometer instrument `in which a preferred form of the present invention is embodied. The instrument shown in Fig. l comprises. a feed roll A carried by a shaftA for advancing a record strip a, which is drawnby the roll A from a record strip supplyroll A5. A

'record is formed on the record stripA a by a pen b supported by a pen carriage The latter comprises a sleeve portion B surrounding a pen carriage supporting and adriage in the position in 'sary or desirable.

arts broken away iusting shaft C which extends parallel to the -feed roll shaft A. The shaft C is formed with a helical groove C receiving a. tooth portion B2 of the sleeve B which in effect is a nut threaded on the shaft C and is moved longitudinally of the shaft C by the rotation of the latter. ports 'a contact 1'. The latter is in the forni of a helix coiled about'and supported on a drum R carried by a shaft R parallel to the feed roll shaft A.

As shown, the pen carriage B is so disposed that it is held by avity in the position in which the contact R, engages the resistance 1*, but additional guiding means maybe provided for more positively holding the carengages the resistance 1', if considered neces- The shafts R and C are geared together. The connecting gearing in the form shown, includes a gear C2 secured to the lefthand end of the shaft C, a gear R2 secured to the leftharid end of theshaft R, and an intermediate gear M`in mesh with the gears C2 and R2.

the pitches of the helical slot C and of rthe helically wound slide wire resistance r are advantageously so related that whenthe shafts R. and Care rotated, the longitudinal movement given the contact BR is the same as would be given the contact if the latter were moved bythe screw action of the helically Wound resistance r. n consequence, when the shafts R and C are rotated, the relative movement of the contact BR and the resist ance r is in the longitudinal direction of the portion of the latter in engagement with the contact. e

rlhe feed roll shaft A is driven from a constantly rotating shaft D by gearing shown as comprising gears D and A2 secured to the' shafts D and A, respectively, and an intermediate idling gear' is the main drive shaft of the instrument and gives motion, as hereinafter described, to the B. shafts C and R as well as to other operative parts of the mechanism, is continuously rotated in the clockwise direction and at a suit- A, The shaft D which.

The pen carriage B also supmember BR which engages. the main potentiometer slide wire resistance which the contact BR able speed by asynchronous motor E which in practice may well be of the type of well known Warren electric clock motor.

The-shafts A, A", C, D, and R, gears M, MA and A", and other parts hereinafter mentioned, are journalledin the side plates X forming a part of the supporting framework of the instrument. As shown in Fig. l, the major portion of the left hand supporting plate X is broken away so as not to obscure adjacent portions of the mechanism. The driving motor E for .the main drive shaft D is mounted on the right hand frame plate X.

The shafts R and C are periodically adjust-- ed angularly in one direction or the other in accordance with the deiection from its neutral position of the pointer F of the galvanometer F forming a part of the potentiometer instrument. The mechanism by which such adjustments are effected includes means for periodically clamping the galvanometer pointer F in the position -which it then occupies, and the engagement of the pointer when so clamped bya selective actuating element of the adjusting mechanism. The periodic clamping of the galvanometer pointer is effected by means of a depressor cam (l carried by the constantly rotating shaft D andserving to depress a clamping element G so that the pointer will begripped between the element G and the straight edge H forming the bottom wall of a slot in a stationary plate H supported by the instrument framework and through which the free end of the pointer F projects. The element G advantageously, and as illustrated, is in the form' of a spring plate, the resiliency of which holds the plate above the path of de.- flection of the pointer F except when the plate is depressed by the cam d.

The adjusting mechanism comprises a rock shaft I above and generally parallel to the pointer F when the latteris in its neutral position, a clutch-disc I secured to the rock shaft I, an arm I2 pivotally mounted on the rock shaft I, and a pawl member z' which is pivotally connected at z" to the arm I2 and forms a pointer engaging extension of the latter. The member i includes a detent portion 2 which is normally urged by a spring 3 into the position in which it` engages the periphery of the clutch disc Il and thuslocksthe member z', arm I2 and the rock shaft I rigidly together. When the rock shaft I is rotated in the counterclockwise direction, as hereinafter explained, to bring the member i into engagement with the galvanometer pointer F', the latter then being clamped between the member G and the straight edge H, the spring 2 yields to permit the turning movement of the member z' and arm I2 to be interrupted without interrupting the rotative movement of the shaft I. As soon as the reverse movement of the shaft I begins the detent i2 again locks the arm I2 and member i to the rock shaft I. y

The rock shaft I is given periodic turning movements in the counterclockwise direction by the shaft D through mechanism comprising a segmental gear D2 carried by the shaft D, a cooperating spur gear K carried by a shaft K parallel to the-shaft D, and an operative connection between the shafts K and I. In the constructionshown in Fig. .l the shafts K and I are operatively connected by a worm K2 carried by shaft K, and aworm gear I'j carried by the shaft I and in mesh with the worm K2. To avoid lost motion the mounting for the shaft I. ispreferably arranged to press the gear I5 snugly against the worm K2. A spring 11, shown as loosely coiled about the shaft I and having one end secured to the shaft and the other to the instrument framework, forms an additional means for preventing lost motion.

Associated with the shaft K is a spring K5 which yieldingly opposes the movement imparted to the shaft K by the vshaft D through the gears D2 and K and which when permitted so to do returns the shaft K and thereby the shaft I to their normal positions. As shown, the spring K5 is a helical spring loosely coiled about the shaft K and having one end secured to the gear K', and its other end anchored to the instrument framework. The normal position of the shaft K which is that shown in Fig. 1, is fixed by the engagement of a stop arm K8 carried by the shaft K with a stationary stop shown as, a projection H2 from the platel H.

The shaft K carries at its opposite ends selectorcams L and LA. The angular positions assumed by these cams at one stage in the operation sequence following each rotative movement imparted the shaft K by the shaft D, determine the angular adjustment, if any, then given to the pen carriage supporting shaft C and to the slide wire resistance supporting shaft R. Whenever the gear D2 engages the gear K', the shaft K is thereby rotated through an angle which may well be 300o or so, before the continued rotation of the shaft D moves the mutilated gear segment D2 out of engagement with the gear K The rotative movement thus imparted to the shaft K gives a corresponding rotative movement to the shaft I. The arm I2 and the pawl member z' turnwith the shaft I until the member i engages the galvanometer pointer F which is then clamped between the i member G and straight edge H. When the ymember z' engages the pointer F the spring s yields and permits just enough turning movement of the member z' about its pivot e", to disengage the clutch disc I so that the latter and the shaft I may continue their rotative movements without carryingthe arm I2 and member z' with them. The part z', as

shown, is so formed and disposed that it has L relation of the arm a gravitational tendency to engage the pointer F in any position of the latter.

As soon as the gear D2 passes out of engagement with the gear K the shaft K starts to turn in the reverse direction under the action of the spring K5, .and this rotative movement of the shaft K eifects a corresponding reverse rotation of the shaft I. The rotative movement of the latter, and thereby the rotative movement of the shaft K,'is interrupted when the pawl member engages a projection G5 on the member G.

The positions of thecams L and LA at this i time determine the extent and direction for angularadjustment of the shafts C and R, and are dependent upon the then position in which the galvanometer pointer F', has been clamped because the latter fixes the angular I2 and the clutch disc I' when those parts 4are -relocked at the beginning of the return movements of the shafts K and I.. The greater'the Vdeflection of the pointer F to the right7 as seen in Fig. 1,.the greater will be the angular movement per- Initted the arm I2 and the awl member z' before the latter engages t e pointer, and the greater will be lthe return movement: of the shafts I and K occurring before the pawl member engages the stop G5 and thereby arrests the return movements ofthe cams'L and LA. After the adjustments of theshafts R and C vrequired by the positions of the cams L and LA are effected, the continued vInovements of the shaft D and cam d release the member G which rises and releases the galvanometer pointer F. The "rising movement of the member G raises the stop G5 and thus permits a further slight movement of. the pawl member under the action of the spring K5.y

The `movement* then permitted the pawl member is suicient to bring the spur 4L n j of the pawl member against a stop H5. This Vturns the member z' about its pivot suiiiciently to disengage the detent 2 from -the periphery of the clutch disc I', and thereby permit the shafts I and K to then complete their return'movements to their normal positionsin vwhich the stop arm-K5 carried by the shaft- K engages the stationary projection H2. When the clamped member G is next depressed by the cam d, the projection G5 cams the pawl member inthe counterclockwise direction suiciently to separate the spur z'4 from the stoppin H5, and thereby permits the spring 5 toV force thefdetent 2 into locking engagement l with the clutch During each period in which the return movement of the shaft K is temporarily vinterrupted by the engagement of the member with the stop G5,`the mechanism collectively controlledy by the cams L and LA efects whatever adjustments of the shaft C and are required by the then position of the gal- `vanometer pointer F. The cam L 'controls the adjustment in the counter-clockwise direction of the shafts R and C which is required when the galvanometer pointer F is clamped in a position at the right of its neutral position. With such galvanometer pointer position, the return movement vof the shaft K will betemporarily arrested by the engagement of the pawl member with the stop G5, with the cam L in such position that j the projection N of a pawl member N will then engage the cam at some point along the rising portion L` L2, L3 of the cam periphery. The distance between a point on the periphery of the cam .L andthe axis of the shaft K progressively increases with the angular distance in the clockwise direction of that point from the point L The pawl member N is pivoted on a pawl lever m journalled on the 'supporting shaft4 l"upper portion of the member N is moved to the left, as seen in Fig. 1, slightly in excess of the amount required to move the lever m into engagement with theV stationary stop A15, whereupon the detent Nzi's l'turned away from the disc M. As soon as any return movement of the upper portion ofithe member N l to the right is permitted1 the detent N2 turns into operative engagement with""the clutch disc M. g y A A cam DN secured to the left hand end of the shaft D periodically engages a projection N5 ofthe member N and moves the pawl and thereby the'pawl lever min the counterclockwise direction.v This movement of the Apawl and pawl lever does not impart a corresponding movement to the gear M. The movement in the. counter-clockwise direction thus imparted to the pawl member N occurs during the period of operation preceding the initial return movement of the shaft K, and

.is just suiiicient to sepa-rate the projection N from the shaft K by a radial distance equal to the distance from the shaft to anyv point along the dwell portion L5, L4, L5 of the cam L. Immediately after the initial return movement of the shaft- K is completed, the continued movement of the cam DN permits a return movement of the 'pawl" N if, the position of the cam L then permits such return .movement If the position of the cam L is then such that its dwell portion L5, L, L5 is in contact with the .projection-N', no return movement of the pawl N can occur. If, however,

placed by a side cam K1o securedto the shaftl l. trols clockwise adjustments of the shafts R the rising portion L L2, L3 of the cam L is then between the shaft K and the projection N', the spring N5 effects whatever return movement of the pawl N is required to bring the projection N into engagement with the periphery of the cam L at the juxta osed point along the rising portion L', L2, 3 of the cam.

Such return movement rotates the gear M in the clockwise direction, and thereby gives counter-clockwise rotations to the' slide wire resistance supporting shaft R, and to the pen carriage adjusting shaft C. of those rotative movements depends upon the distance from the'shaft K of the point along the rising portion Lv', L2 and L3 of the cam L engaged bythe pawl -projection N. The rotative movement of the shaft R rebalances, or tends to rebalance the potentiometer, andthe adjustment of the pen carriage C corresponds to the increase in the value of the quantity measured indicated by the deflection-of lthe galvanometer pointer into the position in which the latter was clamped previous to the adjustment.

When the galvanometer pointer is clamped 'in a position at the left o f its neutral positlon,

indicating the necessit for a clockwise adjustment of the shafts, and C, the position of the cam L is such as to hold the detent N2 of the pawl N out of enagagement with the clutch disc M, but the position of the cam LA is then such as to permit the devices controlled by it to effect the proper clockwise adjustments ofthe shafts Rand C. vThe devices through which the cam LA thus conand C comprise parts N, N, N2, N, N? m,

M, M' and DN, at the right hand side Ofth@4 instrument, which maybe counterparts of the correspondingly designated parts associatedA with the cam L. The intermediate gear M at the right hand side of the instrument, however, gives movement to the shaft R throu h the shaft C, and the gears C2 and M at t e left hand side of the instrument. Furthermore, since the gear M at the right hand side of the instrument is connected to the shaft C v through the gear C20 and an intermediate idling gear MA, the clockwise adjustments given to the gear Mat the right of the instrument, give counterclockwise` rotative movements to the shaft C, and to the shaft R. The cam LA may be a counterpart of .they cam L,

'but is angularly displaced with respect to the latter about the shaft K through anangle 0f180.

In the modification illustrated in Fig. 3, the worm and gear connection between the shafts I and K illustrated inc Fig.v 1, is rei K- and engaged by a cam roller I11 carried by an arirA I12 secured to the shaft I. Theside of the cam K10 engagedby the roller I11 is The magnitude -cally arrestinf` rotated through the worm K2 and gear Il5 in the construction shown in Fig. l. The spring I10 acting on the shaft I holds the roller I11 against the cam K10 at all times and lost motion is thus eliminated.

In the Operation of the instrument disclosed it is tobe noted that while each selective effect depends in a certain general sense upon the .position of the pawl member z' on each engagement of the latter with the lpointer F', in a more specific sense each selective effect is produced by and is dependent directly upon the magnitude of displacement of the member I, when in engagement with the pointer F from the stop G5. Each adj ustment of the shaft R occurs after the completion of the return movement of the member z' from its position of engagement with the pointer F into its position of engagement with the stop G, and depends upon the magnitude of that movement. j

, While in accordance withithe provisions of the statutes, I have illustrated and described the best forms of my invention now known to me, it will be apparent to those skilled in the art that changes may be made in the form of the apparatus disclosed Without departing from* the spirit of my invention, as set forth in the appended claims, and that in some eases certa-in features of mylinvention may be used to advantage Without a corresponding use of vsaid path into a position in which it engages and has its motion arrested by said portion, and mechanism subjected to a selective control efl'ect dependent in magnitude and direction upon the position of said member when its motion is so arrested.

2. The combination with an element deflecting about an axis, of means for periodi- A such deflection comprising a member movable into and out of engagement with said member in a direction transverse to the plane of element deflection, a second member movable in a direction generally transverseto the first mentioned direction into and out of engagement with said element, means for periodically moving said second member between a fixed position in which it is out of engagement with said element into a second position in which it enand desire to secure by Letters l effect dependent in magnitude and direction upon the position of saidf second member when its motion is so arrested.

3. The combination with an element deflecting about an axis, of a member pivoted to turn into engagement with a portion of said element about an axis transverse to the deflection path of saidportion,yieldingmeans for periodically turning said member about its axis to move said member from a position at one end of said deflection path into the position in which it engages and has its movement arrested by said element, and mechanism subjected to a selective control effect dependent in magnitude and direction upon the position of said member when its motion is so arrested. 4

4. The combination with an element deflecting about an axis, t of a deflection restraining member, means for periodically moving said member into and out of restraining engagement with said element, a second member pivoted to turn about an axis transverse to the first mentioned axis and generally transverse to the direction of movement of the first mentioned member, means for periodically turning said second member from a position out of the path of deflection of said element into a position in which it engages and has its motion arrested by said ellement, and mechanism subjected to a selective control' effect depending` in magnitude and .direction upon the position of said second member when it engages said element.

5. The combination with a deflecting element, of a member periodically given to and fro movements of equal magnitudes,`means actuated by the movements of said member and controlled bythe position of said element for temporarily arresting each movementl of said member in one direction after an initial portion of said movement varying in magnitude with the deflection of sai-d element, and

mechanism selectively actuated in accordance with the position of said member when so temporarily arrested.

'1 6. The combination with a deflecting element, of a member periodically given to and fro movements, means actuated by the movements of'said member and controlled by the deflection of saidelement for temporarily arresting each movement of said member in one direction after an initial portion of the last mentioned movement, mechanism selectively actuated in accordance with the position of said memberl When'its movement is so arrested, and means for actuating the first mentioned means/@to4 permit said member to complete its movement in said one direction.

7. Y.The combination with a deflecting ele ment, of a member periodically given to and element in oneposition of the latter,

fro movements, means actuated by each movement of said member in one'direction and conl trolled by the position of said element for I temporarily arresting the following return movement of said member after an initial portion thereof varying in magnitude with z the position of said element, and mechanism selectively actuated in accordance with the position of said member when its return position is temporarily arrested. y

8, rI he combination with a deflecting element-of a member, means for periodically j movingsaid member back and forth between two positions, means including a part moved by said member into engagement with said element on each such movement of said member in one direction, for temporarily arresting the movement of said member in the opposite direction after an initial portion ofthe last mentioned movement varying in magnitude with the position of said element when engaged by said part, and mechanism selectively actuated in accordance with the position of said member when its movement is so arrested. 90

9. The combination with a deflecting element, 4of a relay mechanism controlled by the defiections of said element and comprising a member periodically moved back and forth between two positions, an element engaging part, means normally connecting said part to said member to share the movements of the latter and yielding to permit said part to be arrested by vsaid element without arresting the movement of said member as the latter moves 100 from onev of' said positions into the other,

' means engaging said part and arresting its return movement and that of said member when the completion of the return movement of the latter.

. 10. The combination with a deflecting element, of a constantly rotating shaft, a second shaft, means connecting said shafts through which the first mentioned shaft intermittently advances and releases said sec-4 x15 ond shaft, means tending to return said second shaft to an initial position when released, and means including a part moved into engagement with said element when said second shaft is advanced for temporarily arresting its return movement after an initial portion thereof dependent in magnitude upon the position of said element.

11. Thecombination with an element deflecting about an axis, of a shaft extending transversely to said axis and parallel to said a second shaft transverse to the first mentioned shaft, means through which rotative movements of said second shaft give corresponding movemounted on 'the first mentioned shaft and moved on each movement of the latter in one direction, into engagement with said element for arresting the movement in the opposite direction of said shaft after aninitial portion thereof dependent on the position of said element.

12. The combination with an element defiecting about an axis, of means periodically engaging said element and holding it against deflection, a shaft extending transversely to the pivotal axis of said element and parallel to said element in one position of the latter, means giving said shaft periodical oscillatory movements of constant'magnitude, an arm mounted on said shaft, means normally connecting said shaft and arm to cause the latter to share the movements of the shaft, said means yielding to permit further turning movement of the shaft in one direction after said part engages said element, means engaging said arm after a return movement` of the latter into a. predetermined position and thereby temporarily arresting the return movement of said arm and shaft, means selectively controlled by the position of said shaft when so arrested, and means for periodically adjusting the second mentioned means to permit a completion of the return movement of said shaft.

13. The combination with a. deflecting element, of an oscillating shaft, means for periodically holding said shaft in an angular po.

sition depending upon the then deiiection of said element, a pair of similar cams -mounted on said shaft, each comprising. a rising portion and a dwell portion, cam engaging ele-v ments, means tending to move said elements toward said cams during each period in which the latter is held in saidangular'position,

said ,cams and elements being so relatively arranged that the dwell of one cam prevents movement of one of said elements toward said cam when the rising portion ofthe other cam permits the other element to move toward the last mentioned cam, and means selectively actuated bysaid elements according to their p movements toward said cams.`

14. The combination with a defiectingele- K ment, of a member extending through the plane of defiection of said element and movable along the deiiection path of a portion of said element into and out ofengagementwith said portion, means for periodically movingsaid member from a position at one end o f said path into a position in which it engages and has its motion arrested by said portion, and mechanism subjected .to a selective control effect dependent in magnitude and direction upon the displacement of said member from said rested.

position when its motionis so ar` 15. The combination with an element deflecting about an axis, of means for periodically arresting such deflection comprising a member movable into and out of engagement .with said member in a direction transverse toithe plane of element deflection, a second member movable in a direction generally transverse to the first mentioned direction into and out of engagement with said element, means for periodically moving said second member between a iixed position in which it is out of engagement with said element into a second position in which it engages and has its motion arrested by said element during a period in which the latter is engaged by the first mentioned member, and mechanism subjectedto a selective control effect following each movement of said second member into such second position and dependent in magnitude and direction upon the distance between the last mentioned position and said fixed position.

16. The combination with an element deflecting about an axis, of a member pivoted to turn'into engagement lwith a portion of said element about an axis transverse to the deflection path of said portion, yielding ymeans for periodically turning said member about its `axis to move said member from a position at one end of said-deflection path into the position in which it engages and has its movement arrested by said element, and mechanism subjected to a selective control effect 'dependent in ma itude and direction upon ythe magnitude o the movement required to element into a position in which it engages.l 4

and has its motion arrested by said element, and mechanism subjected toI a selective control effect dependent in magnitude and direction upon the displacement of said second member when it engages said element from lthefirst mentioned osition.

18. The combination with a delecting ele` i ment, of a member periodically given to and fro movementsof equal magnitudes, means actuated b the movements of said member and controil for temporarily arresting each movement of said member in one direction after an initial portion of said movement varying in magnitude with the deflection of said element, and

mechanism selectively actuated in accordance l with the magnitude of said portion.

19. The combination with an element havV ed by the position of said element ing a range of deiection including a portionl at each side of a neutral position, of a member extending through the plane of deiection of said element and movable along the deflection path travelled by a portion of said element as the latter deflects through said range, means for periodically moving Said member from a position at one end of said path into a. position 1n Whlch 1t engages and has its motion arrested by said portion, and mechanism subjected to a selective control effect dependent in magnitude and direction upon the position in said range occupied by said element at the time When the latter is engaged by and arrests the'motion of said member.

Signed at Philadelphia, in the county of Philadelphia and State of Pennsylvania, this 13th day of June, A. D. 1930.

IVAN I. EREMEEFF. 

